The present invention is related to the field of tape guide mechanisms for guiding a tape media across a transducer.
Automatic loading tape drives employ various mechanisms to manipulate magnetic tape media onto a suitable guide path to ensure stable tape media motion past a magnetic read-write head. Existing guide mechanism designs are typically complex and often occupy excessive amounts of volume within a given tape drive. Complex tape guide mechanisms have several disadvantages. Generally, there is a low reliability in such guide mechanisms due to the large number of moving mechanical parts. Some complex designs capture the tape media in such a way that recovering the tape media after a loss of power, mechanical failure, or other malfunction is exceptionally difficult. Other complex guide mechanism designs result in acute wrap angles and multiple points of contact with the tape media and can adversely affect tape media and head wear. In particular, guide mechanisms that repeatedly contact the magnetic side of the tape media can damage the magnetic media over time resulting in loss of data.
What is desired is a simple mechanism that provides a stable tape path, occupies minimal volume, and is easily adapted into existing or new tape drive designs. It is known in the art that the guide path should direct the tape media along a gentle arc to provide transverse stability at the read-write head. Guide mechanisms contacts with the tape media are preferably from the substrate side to minimize the possibility of damage to the magnetic material and subsequent data loss. Finally, the guide mechanism should hold the tape media so that the tape media can be extracted without damage from the tape drive in the event of a mechanical failure or power loss.
The present invention is a guide mechanism and methods of operating the guide mechanism to position and guide a tape media across the face of a transducer and onto a first reel. The mechanism comprises a guide member that is rotatably mounted about the first reel. A tape guide surface is provided along the outer edge of the guide member. The tape guide surface defines a longitudinal path for the tape media across the transducer. The tape guide surface is also shaped to provide transverse support and guidance for the tape media. An opening is provided in the tape guide surface to allow the tape media to transition between the tape guide surface and the first reel. An optional recession is formed in the tape guide surface that allows the transducer to intrude into the longitudinal path of the tape media and thereby engage the tape media without compressing the tape media between the transducer and the tape guide surface.
In operation in a tape drive configured for single reel data cartridges, the tape media is first threaded from the data cartridge through the opening in the tape guide surface and attached to the first reel. The guide member is then rotated in a wrapping direction causing the tape media to wrap onto the tape guide surface and adjacent to the transducer. After the recession in the tape guide surface has been aligned with the transducer, the transducer is moved to engage the tape media. From this point, the tape media can be moved past the transducer at normal speeds along the longitudinal path defined by the tape guide surface.
The tape media can be unwrapped from the tape guide surface with any amount of tape media spooled on the first reel. A process of unwrapping begins with the disengagement of the transducer from the tape media. The guide member is then rotated in an unwrapping direction until the tape media has been unwrapped from the tape guide surface. Whatever tape media remains spooled on the reel is wound back into the cartridge and then the leader shuttle for the tape media is disengaged from the first reel.
The ability to wrap and unwrap the tape media from the tape guide surface with any amount of tape media spooled on the first reel allows for high speed movement of the tape media without any friction associated with the tape guide surface. Rapid movement to a desired location on the tape media is accomplished by first unwrapping the tape media from the tape guide surface. The tape media is then spooled or unspooled from the first reel at high speeds until the desired location on the tape media is proximate the opening in the tape guide surface. The tape media is then wrapped back onto the tape guide surface. Finally, the tape media is moved across the tape guide surface until the desired location on the tape media is aligned with the transducer.
Accordingly, it is an object of the present invention to provide a guide mechanism that wraps a tape media around itself to serve as a longitudinal path that guides the tape media across a transducer and onto a reel.
Another object of the present invention is to provide a method of operation for the guide mechanism to position the tape media adjacent to the transducer by rotating the guide mechanism.
Yet another object of the present invention is to provide a method for rapidly aligning a predetermined location on the tape media with the transducer wherein high speed tape media movement occurs while the tape media is out of contact with the guide mechanism.
These and other objects, features and advantages, will be readily apparent upon consideration of the following detailed description of the invention in conjunction with the accompanying drawings.